Citizens for Working America is not the biggest or the most influential of the super PACs, but it may provide one of the clearest illustrations of how hard it is to track the shadowy organizations that have sprung up to influence elections in the wake of the Supreme Court's landmark Citizens United decision.

The group first surfaced in 2010, when it became one of the big spenders in a successful GOP campaign to unseat House Budget Committee Chairman John Spratt from a seat that the South Carolina Democrat occupied for 28 years.

But the group never spent any money on Bachmann's behalf, and on Christmas Eve, it defected to Mitt Romney, making a $475,000 TV ad buy in Iowa to tout his conservative credentials just days before Republicans there cast the first votes of the 2012 presidential election.

Following the footsteps of Citizens for a Working America PAC. Click on the markers for more information.

Learning who is behind Citizens for a Working America is not easy. The website listed on its FEC forms isn't working. In a Sept. 22 statement of organization with the FEC, the PAC listed as its address a half-million-dollar waterfront property located in Lancaster, Va., owned by Norm Cummings. Cummings is a long-time Republican political operative who recently worked for Jane Norton, who lost a 2010 race for the Colorado GOP Senate nomination to tea party favorite Ken Buck. (Buck, in turn, lost his bid to unseat Sen. Michael Bennet, D-Colo.) But in a phone conversation with Sunlight, Cummings now said the PAC is headquartered in Dayton, Ohio.

Jeremy Hughes, a Kentucky political consultant who worked on the unsuccessful Senate campaign of Trey Grayson (who lost the Republican primary to now-Sen. Rand Paul, R-Ky., son of GOP presidential candidate Ron Paul) was the PAC's treasurer for the 2010 cycle but has since left.

In 2010, Cummings told ABC News his PAC existed to fill a leadership void left by then-Republican National Committee Chairman Michael Steele, who alienated many big GOP donors. Steele has since been replaced as RNC chair by establishment favorite Reince Priebus, but Citizens for a Working America shows no signs of slowing down.

Langdon did not return messages from Sunlight. Cummings, reached on his cell phone, described the PAC as "dedicated to the support of job creation and free enterprise," and was noncommittal about whether his group would make another ad buy for Romney.

"I would not discount that," Cummings said. "This is a very fluid environment." He was unforthcoming about the group's sources of funding. The PAC will have to file a report at the end of the month, but that doesn't guarantee any revelations: